Call of Duty: MW3 Campaign Walkthrough Part 1: Black Tuesday

When you launch COD: Modern Warfare 3, You have three modes available: Special Ops, Campaign, and Multiplayer. It is recommended you start with the Campaign mode.

Choose "New Game" on the next screen.

Here you will select the difficulty level:
Recruit: For players who are new to first person action games
Regular: Your abilities in combat will be tested
Hardened: Your skills will be strained
Veteran: You will not survive

If this is absolutely the first time you have played a first person shooter, you should choose Recruit. But if you have even a little experience, we recommend playing on Regular difficulty, which is not very hard, yet on the same time provides some degree of challenge. If you follow this walkthrough you should make it alright. If it does end up being too hard, you can always lower the difficulty from the game menu.

Starting the campaign will give you your first trophy/achievement: Back in the Fight (Start the Single Player Campaign on any difficulty)

There will be a cutscene next.

The Russians are using electronic countermeasures to jam our comms and guidance systems. The primary emission tower is on top of the Stock Exchange. I need your team to destroy it. The Jammer is full spectrum. So until it's down, you will have no radio contact.
I have ground assets to get you close
Copy All, We'll get it done

"Black Tuesday"
Sgt. Derek "Frost" Westbrook
August 17th 10:18:02
Delta Force
Manhattan, New York

You start as an RPG rocket hits your armored truck. You exit the truck Sandman throws you an ammunition cartridge which you load into your M4A1 gun.  Jammer is 500 meters north.

Your first mission objective is to fight your way to the stock exchange. Start fighting you way through. Follow your teammates, and make sure to take cover along the way. Shoot the enemy soldiers.

If you see blood splatters it means you are being hit! If too much of your screen is covered in red it means you are about to die. IMMEDIATELY find cover and recover from the shots.

Keep following the waypoint. You will reach a junction and a armored vehicle will come and help you out a bit with its machine gun. Turn right.

Your objective now is to Flank the Russians on Wall Street.

Suddenly an aircraft will attack you. Immediately go right and off the street, into the building. Follow Sandman (you should see a dot that says "FOLLOW"). He will kick in a door. Enter and kill the enemies inside that area. Keep fighting your way through the building. As you exit the building he will tell you to throw a flashbang, follow the on screen prompts.

You are now with your squad outside again. Climb up the stairs and enter another building. There are shooters in the store below.  Get rid of them. Grinch will take up overwatch while you and Sandman clear the store. Use gre

Head west to the street, and continue fighting your way to the stock exchange.

The enemies are dug in. You should switch to the XM25 and flush them out.

Watch out for grenades being thrown at you.

Memorial building will be to the North.

Enter the stock exchange building. Your team will secure the lobby while you hit the trading floor. Your goal now is to make it to the stock exchange roof. Follow your teammates up the escalator. There will be some enemies behind a window, shoot them.

Follow Sandman up the stair, onto the balcony, and up the rail.

Climg the ladder to the roof. The jamming system is up on the second tier.

Your goal now is to plant a thermite charge  on the Jammer. Make your way to the Jammer while your teammates cover.
Put the thermite charge on the Jamming system's power supply, then detonate the thermite charge.

Radio contact is restored! Overlord is sending a Blackhawk Helicopter to your location

Use the Predator to take out enemy forces. Use it to take out the enemy Hind. After you shoot the missiles, guide them to your targets.

Board the Black Hawk. Use the machine gun to shoot enemies hiding on rooftops. Shoot down the enemy helicopters that come and attack you. At some stage your copter will be hit, but don't quit the game yet! It's part of the story. Your pilot will recover and you will approach the New York Harbor for your next mission.